Hydrogen atomic clocks

1
Hydrogen atomic clocks
J. Mauricio López R.
División de Tiempo y Frecuencia
2
Outline
0. Introduction
1. The Maser effect
2. Hydrogen Maser clocks
3. Frequency stability of a Hydrogen maser clock
4. Metrology applications
5. Conclustions
3
INTRODUCTION
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The Nobel Prize in Physics 1989
"for the invention of the separated oscillatory
fields method and its use in the hydrogen maser
and other atomic clocks"
"for the development of the ion trap technique"
                               
                               
                               
Norman F. Ramsey
Hans G. Dehmelt
Wolfgang Paul
    1/2 of the prize
    1/4 of the prize
    1/4 of the prize
USA
USA
Federal Republic of Germany
Harvard University Cambridge, MA, USA
University of Washington Seattle, WA, USA
University of Bonn Bonn, Federal Republic of
Germany
b.1915
b.1922
b.1913d.1993
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(No Transcript)
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1958 invensión del láser
Infrared and optical Masers, Phys. Rev. , 1958
Charles H. Townes
Bell Labs
Arthur L. Schawlow
Bell Labs
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The MASER effect
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Spontaneous emission
Quantum system of two energy states
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Spontaneous emission
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Spontaneous emission
Feymann diagram for the spontaneous emission
effect
11
Stimulated emission
Quantum system of two energy states
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Stimulated emission
Feymann diagram for the stimulated emission
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Efecto Láser
The three basic energy levels configuration for a
laser effect
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Laser effect
-Light amplification -
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Basic elements of a Maser clock
Maser
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Energy levels of a HeNe laser
Collisions He-Ne
Long life time state
E2
E3
20 eV
E1
18 eV
Laser light 632.8 nm
Pumping (electric discharge)
Energy
Quick decay
Ground state
0 eV
Energy levels of He
Energy levels of Ne
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Energy levels of a Hydrogen maser clock
F2
P 3/2
23.7 MHz
F1
2P
10.969 GHz
F1
2S
177.6 MHz
F0
121.6 nm
1.0578 GHz
F1
P 1/2
59.19 MHz
F0
F1
1S
1.420 GHz
F0
Electric interaction
Fine structure
Hyperfine structure
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Hydrogemn Masers realization
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Basic architecture of a Hydrogen Maser clock
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Quantum states selection
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Frequency synthesis chain for a Hydrogen Maser
clock
Mixer
20.405 752 MHz
20.405 752 MHz
Phase lock loop
5 MHz Frequency output
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Actual architecture of a Hydrogen maser clock
(KVARZ)
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Active Hydrogen Maser
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Active Hydrogen Maser
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Frequency stability of a Hydrogen maser clock
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Frequency stability of atomic clocks
-9
Quartz
-10
-11
Rubidium
Log (?y(?))
-12
-13
Cesium
-14
-15
Hydrogen maser
-16
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
Log (?), seconds
1 Day
1 Month
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Hydrogen maser Metrology applications
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2d Master Clock (Hydrogen Maser)
n-1 independent measurements
...
CENAMs clock ensemble of the ETP-1
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x23x21-x31
...
x21
x31
xn1
Master clock
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Time scale generation philosophy
-9
-10
-11
Log (?y(?))
-12
-13
-14
-15
-16
0

2
3
4
5
6
7
8
9
7.0
Log (?), seconds
1 Day
1 Month
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Hydrogen atomic clocks
J. Mauricio López R.
División de Tiempo y Frecuencia
.
mauricio.lopez_at_cenam.mx
52 [phone]